It's 87.97 days of the orbital period going round the sun it's days of the shortest of all planets in the solar system.
Answer: The car has a kinetic energy (because it's in motion) of: 
Explanation:





Yes it is valid all the times under the consideration of acceleration due to gravity .it is not valid on space where there is no influence of gravity
PART A)
By Snell's law we know that

here we know that



now from above equation we have


so it will refract by angle 39.3 degree
PART B)
Here as we can see that image formed on the other side of lens
So it is a real and inverted image
Also we can see that size of image is lesser than the size of object here
Here we can use concave mirror to form same type of real and inverted image
PART C)
As per the mirror formula we know that



so image will form at 30 cm from mirror
it is virtual image and smaller in size
Answer: 1.76 Nm
Explanation:
If the force pulls horizontally, this means that the force is tangent to the disk at any point of the string unwinding process, so the distance d is irrelevant.
In this case, the torque is directly given by the product of the force times the distance perpendicular to the center of the disk, which is just the radius, as follows:
τ = F * r = 16 N. (0.11) m = 1.76 Nm